Mask structure



Nov. 28, 1944. E, DU GAN 2,363,844

MASK STRUCTURE Filed Jan. 15, 1943 INVENTOR.

JAMES EDWARD DUGGAN BY B 1%! KW ATTORNEYS i are painted or plated.

Patented Nov. 28, 1944 .UN'IT'ED] STATES PATENT 1 OFFICE 1 j r 2,363,844 I MASK STRUCTURE James Edward I Juggan, Indianapolis, Ind. Application January 15, 1942, Serial No. 472,517, 1 (CI. 91-65) 6 Claims.

This invention relates generally to devices that are used during painting or plating operations to protect, certain portions of articles from paint or plating material applied to adjacent portions thereof, and refers more particularly to masks for preventing paint or plating mate'- rial from contacting or passing onto the working surfaces of the teeth of bevel gears, bevel pinions and the like when other portions of such gears One of the essential objects of the invention is to provide a mask capable of thoroughly protecting the working surfaces of the teeth mentioned without in any way interfering with the painting or plating operation.

Another object is to provide a mask that may be easily and quickly applied to and removed from the portions to be protected without marring or impairing any part of the gears.

Another object is to provide a mask that may be used repeatedly without being scrapped.

Another object is to provide a mask that is simple in construction, economical to manufacture, and efiicient in operation.

Other objects, advantages and novel details of construction of this invention will be made more apparent as this description proceeds, especially when considered in connection with the accompanying drawing, wherein:

Figure 1 is an edge elevationalview of a mask embodying my invention applied to a bevel gear,

with parts broken away and in section;

'- Figure 2 is a top plan view "of the mask;

Figure 3 is a bottom plan view of themask; Figure 4 is a vertical cross sectional view through the mask;

Figure 5 is a view similar to Figure 1 but showing an inverted bevel gear provided with the mask embodying my invention.

Referring now to the drawing, A is a ring type bevel gear having an annular body provided on a beveled surface thereof with circumferentially spaced transversely extending helical teeth. II and having a. laterally projecting interiorly splined hub 12, and B is a mask embodying my invention adapted to protect the helical teeth I l of the gear from paint or plating material applied to other portions of the gear. In the present instance the gear A is a power gear for an airplane propeller and ordinarily has platingmaterial such as copper plating upon all portions thereof except the teeth II which are usually highly polished for proper engagement with the teeth (not shown) of a meshing gear.

In the past, due to the absence from the mar- 'ket of a mask such as that forming the subject matter of. this application, some manufacturers found it necessary to plate the entire gear, including the teeth H thereof, and then to return the gearto the machine shop where the plating material on the teethwas removedbyla grinding operation. The teeth of i the gear were then polished. Thus, such procedure required con siderable time, labor and material andhas proven unsatisfactory. For example, during the grinding operation or other'handling of the gear back and forth, one or more, portions of the plating material on the body of the gear were sometimes accidentally removed or otherwise damaged. Moreover, the planting material removedby the grinding operation from the teeth of the gear was usually wasted. Ordinarily the plating material was applied to the whole gear before it was subjected to the usual hardening operation, hence additional handling of the gear was required before the plating material'on the.

teeth thereof was subjected to the grinding operation mentioned.

i To avoid the objections of the procedure just I described othermanufacturers covered the teeth onlyof the gear with wax before the other portions thereof such .as the body I0. and hub l2 were. plated or painted. Ordinarily this, wax coating or covering was obtained by dipping the teeth of the gear in hot wax in a suitable container, then withdrawing the wax covered teeth from the container, and then allowing the wax to cool and harden on the teeth. However such dipping operations were by no means accurate, hence portionsof the body In or hub l2 to be plated were sometimes accidentally covered by the wax intended forthe teeth only. This necessitated the removal of the wax from the body orhub of the gear before it could be plated. Moreover, the wax sometimes did not remain on the teeth during the plating .or painting opera tion, hence the exposed portions of the teeth received accidentally deposits of plating material or paint that had to be removed as aforesaid. Accordingly, this procedure was likewise unsatisfactory,

j In the present instance, however, I have overcome entirely the objections mentioned by the provision of a one piece mask B that may be easily and quickly applied to a gear to accurately and effectively protect the teeth ll thereof from paint or plating material applied to other portions of the gear. Preferably this mask B is in dished portion thereof for receiving the teeth ll Preferably these webs I! in crease slightly in depth from the upper flange I5 to the lower flange l6 and are terminally 0011-" nected thereto. To insure a'tight seal with the body of the gear, the flanges l and I6 are provided at their inner edges withcircumferentially extending inturned angular clamping lips 18 and [9, respectively.

Inuse, when the mask B is applied to the gear A,a'sillustratedin Figure 1, the bod H) of the gear is received between the flanges I5 and It on i the underside of the body I4 of the mask, so that thehelical teeth ll of the gear are received in the 'helical'grooves that are provided in the mask between the helical webs I 1 thereof. Likewise, thehelical webs ll of the mask fit snugly between'the helical teeth H of the gear, while the clamping lips'l8 and l9'of themask bear firmly against and provide knife-like annular edges at opposite sides of the body ll) of the gear. As a result, the mask B covers and protects the helical teeth H of the gear A against paint er platingmaterial applied to the other portionsiof the gear without interfering with the application of plating material or paint to such other portions. 7

Thus, from the foregoing, it will be apparent that the entire gear A maybe completely machined, finished and polished before being plated or painted because the mask ,3 effectively protects the working surfacesof the teeth ll thereof and may be applied to the gear after it is polished without marring the 'finish'thereof, and maybe removedfrom the gear after the paintingKQr 'plating operation has been completed without marring the plating material or paint that has been applied to the gear. Moreover, the

same mask B may be used over and over again as aforesaid on different gears without being scrapped. As a result, a substantial saving in time, labor and material is effected. When the mask 13 is used, the gear A protected thereby may be subjected before orafter' the plating'or painting operation to the usual hardening operation to complete it for the market.

In Figure 5 Ihave illustrated an inverted bevel gear 30 having helical teeth 3| that are protected by'a similar mask B. In this construction, the mask B'is slipped down the shaft 32 onto the bevelgear 3i] and engaged With the latter as in-Figurel.

What I claim as my invention is v 1. A mask for protectingthe working surfaces of the teethjof a bevel gear from plating material, paintand the like applied to other portions of said gear, comprising asolid dished annulus of resilient' material having a circumferentially extending channel within the dished portion there-,

of for receiving the teeth of said gear, the base of the channel being provided between opposite sides of the channel with circumferentially spaced transversely extending webs for masking engagement with the working surfaces of the teeth of said gear, opposite sides of said channel being provided at the free edges thereof with circumferentially extending inwardly directed lips for sealing engagement with the gear upon opposite sidesof the teeth thereof.

2. A mask of the class described formed entirely of resilient material and comprising a one piece solid annulus having a dished portion provided with a circumferentially extending chan-. nel, the base of said channel being provided I between opposite sides thereof with circumferentiallyspaced transversely extending webs;

3. A mask of the class described formed entirely of resilient material and comprising a one piece solid annulus having a dished portion pro vided with a circumferentially extending channel, the base of said channel being provided between opposite sides thereof with circumferentially, spaced transversely extending Webs, opposite sides of the channel being provided at the free edges thereof with circumferentially extending inturned clamping lips.

l. Means for protecting the teeth of a bevel gear from paint or plating material while such paint or plating material is applied to other portions of said gear, comprising a one-piece annular masking element 'formed'entirely of resilient material and having a circumferentially extending channel for receiving the teeth and adjacent body portion of said gear and provided withinsaid channel between opposite-sides thereof-with circumferentially spaced transversely extending webs for meshing engagement with the teeth of said gear, opposite sides of the channel being provided at the inner edges thereof with means for sealing engagementwith the body portion of said ear.

6. Means for protecting the teeth of a bevel gear from paint or plating material while such paint or plating material is applied to other portions of said gear, comprising a one-piece annu.

lar masking element formed entirely of resilient material and having a c'ircumferentially extending channelfor receiving the teeth and adjacent body portion of said gear and provided within said channel between opposite sides thereof with circumferentially spaced transversely extending webs for meshing engagement with the teeth of said gear, opposite sides of the channel being provided at the inner edges thereof with circumferentially extending inturned ,clamping-lips for sealing engagementwith the body r- 1 a 7 JAMES EDWARD DUGG'AN.

portion of said 

